In fluorescence microscopy, the specimens to be examined are generally stained with dyes that, as a result of excitation by means of an excitation light beam, emit detected light that has a spectral composition characteristic of the dye. Using a scanning microscope, it is possible to detect in a spectral region from 300 nm to approx. 1000 nm. The special emission spectra of the dyes lie somewhere in the spectral region from 300 nm to 1100 nm. The entire spectral region is thus scanned in order to locate the special spectra. This is time-consuming, and the radiation stress (e.g. bleaching, thermal damage, etc.) on the specimens being examined is high. Those specimens are often no longer usable for further examinations. Since a large expenditure of time and money is required to produce specimens for microscopic examination, the disadvantage of existing systems is that the specimens are exhausted by phototoxic effects simply by looking for the special spectra, without thereby obtaining experimental results or data.
German Patent Application DE 100 06 800.6 discloses an apparatus for selecting and detecting at least one spectral region of a spectrally spread light beam (spectral photometer module). Selection means embodied as sliders are provided in the spread-out light beam in order thereby to deflect portions of the spread-out light beam onto various detectors. The signals of the detectors are then used for image generation. DE 100 06 800.6 does not disclose actuation of the sliders in such a way as to make possible rapid and reliable detection of a special spectrum.